Amazon has upped its free shipping minimum order to $35 just ahead of the holiday season.

Amazon's free shipping minimum order has been $25 for the last decade, but the online retail giant has raised the minimum by $10 starting yesterday. This means that customers must purchase a minimum of $35 on eligible items and have it shipped to any address in the 50 states in order to receive free shipping.

Amazon, which announced that the free shipping minimum order would increase around the holidays earlier this year, is likely trying raising the minimum to keep up with the competition. Retailers like Target and Wal-Mart offer free shipping on purchases over $50, for example.

In the last three months of 2012, Amazon spent almost $1.8 billion USD on shipping. Clearly, shipping isn't cheap and the added $10 will help.

This is also likely an effort to push customers toward an Amazon Prime membership. It only costs $79 per year and offers free two-day shipping on all eligible items with no minimum order size. Prime members also receive access to the company's streaming movie and TV show library.